Trastuzumab for the treatment of salivary duct carcinoma
Sewanti A Limaye1, Marshall R Posner, Jeffrey F Krane
1Department of Medical Oncology, Dana-Farber Cancer Institute/Harvard Medical School, Boston, Massachusetts 02115, USA. sewantia_limaye@dfci.harvard.edu
Objective:
Salivary duct carcinoma (SDC) is a rare and aggressive malignancy with high mortality and poor response to treatment. A significant fraction of SDCs are HER2 positive. This retrospective review examines HER2 testing in SDC and the outcome of trastuzumab-based therapy in adjuvant and palliative settings.
Methods:
A total of 13 patients with SDC and HER2/neu expression by immunohistochemistry of 1-3+ were treated with trastuzumab in adjuvant (n = 8) or palliative (n = 5) setting. Adjuvant therapy consisted of concurrent radiation and chemotherapy with weekly paclitaxel, carboplatin, and trastuzumab (TCH) for 6 weeks followed by TCH for 12 weeks and trastuzumab alone for 1 year. Palliative treatment for metastatic disease consisted of TCH every 3 weeks for 6 cycles followed by trastuzumab for variable time periods with or without second-line chemotherapy for progression. All patients had fluorescence in situ hybridization testing for HER2/neu gene amplification.
Results:
The median duration of follow-up was 27 months (range: 8-48 months). In all, 62% of adjuvant patients (5/8) had no evidence of disease more than 2 years from completion of therapy. All patients with metastatic disease (5/5 patients) responded to treatment with TCH. One patient achieved a complete response and remains with no evidence of disease 52 months after initiation of TCH. The median duration of response was 18 months (range: 8-52 months).
Conclusion:
HER2/neu positivity and treatment with trastuzumab correlated well with long-term survival and response in our patients. Based on this data, we propose that HER2/neu status be examined routinely in all patients with SDCs and the treatment be directed accordingly.
Insights
Salivary duct carcinoma (SDC) patients with HER2 positivity showed improved outcomes with trastuzumab-based therapy. Routine HER2 testing is recommended for SDC treatment decisions.
Area of Science:
- Oncology
- Medical Malignancies
Background:
- Salivary duct carcinoma (SDC) is an aggressive cancer with poor prognosis.
- A notable proportion of SDCs exhibit HER2 positivity, suggesting a potential therapeutic target.
Purpose of the Study:
- To investigate HER2 testing practices in SDC.
- To evaluate the efficacy of trastuzumab-based therapy in both adjuvant and palliative settings for SDC patients.
Main Methods:
- Retrospective review of 13 SDC patients with HER2/neu expression (IHC 1-3+).
- Patients received trastuzumab in adjuvant (n=8) or palliative (n=5) settings, often with paclitaxel and carboplatin (TCH regimen).
- All patients underwent fluorescence in situ hybridization (FISH) for HER2/neu gene amplification.
Main Results:
- In the adjuvant group, 62% (5/8) achieved no evidence of disease over 2 years post-therapy.
- All 5 patients with metastatic disease responded to TCH therapy, with a median response duration of 18 months.
- One patient with metastatic disease achieved a complete response and remains disease-free at 52 months.
Conclusions:
- HER2/neu positivity in SDC correlates with favorable long-term survival and treatment response to trastuzumab.
- Routine HER2/neu status examination in SDC patients is proposed to guide treatment strategies.
- Trastuzumab-based therapy demonstrates significant efficacy in both adjuvant and palliative management of HER2-positive SDC.
